Method and apparatus for providing after tax valuation of tax-exempt bonds

ABSTRACT

Methods and systems are disclosed for determining valuation and risk analysis of municipal debt instruments on an after-tax basis. In one embodiment, bond terms, yield curve and interest rate volatility data are received for a set of bonds. Additionally, IRS treatment data and applicable tax rates for the set of bonds and a purchaser of the bonds are also received. Theoretical tax-neutral values of the bonds are calculated using a buy-and-hold methodology, wherein the tax-neutral value comprises the price of the at least one municipal debt offering such that its discounted after-tax value equals the price. A theoretical maximum after-tax values of the bonds are also calculated using a recursive valuation path-dependent methodology. Optimal bond management is determined using the calculated theoretical tax-neutral values and maximum after-tax values of the bonds.

TECHNICAL FIELD

The field of the disclosure generally relates to the valuation of bondsand, more particularly, to determining valuation and risk analysis ofmunicipal debt instruments, such as bonds.

BACKGROUND

While interest on municipal bonds is generally exempt from federalincome taxes, capital gains and losses are subject to complex taxtreatment that affects a bond's performance. For example, because thegain on a bond purchased at a discount (to the relevant basis) and heldto maturity (buy-and-hold) is subject to taxes, the after-tax yield ofthe investment will be lower than the pretax yield. On the other hand,investors may be able to improve performance over a buy-and-hold policyby selling the bond and recognizing losses for tax purposes when thebond's price declines sufficiently and reinvesting the proceeds in alike security.

The effect of taxes is recognized by investors. For example, the pricesof tax-exempt bonds are routinely converted to so-called after-tax cashflow yields, with the underlying assumption being that the bonds will beheld to maturity. Converting a bond's price to an after-tax yield isstraightforward, and it allows investors to compare the yields ofalternative investments.

It is known that active tax management can produce superior performanceover a conventional buy-and-hold policy. Accordingly, there is a needfor a more accurate and analytical system and methodology to implementbond valuation and risk management, i.e., it provides the sell signalsrequired for optimal management. Any added value derived from optimalmanagement, the so-called tax option, can be a by-product of theanalysis.

SUMMARY OF THE DISCLOSURE

The present disclosure is directed to exemplary methods, exemplaryapparatus and exemplary systems that determine valuation and riskanalysis for municipal debt instruments such as, but not limited to,municipal bonds.

Embodiments disclosed herein encapsulate determining the theoreticaltax-neutral value (explained below) and the maximum value of tax-exemptbonds, given standard market-related information (relevant yield curveand interest rate volatility) and tax considerations (IRS treatment andapplicable tax rates). The tax-neutral value is determined assumingbuy-and-hold strategy, while the maximum value is derived assumingoptimal tax management.

A computer-implemented method of calculating the after-tax value of amunicipal debt instrument includes: receiving, by a computing systemincluding a processor and a data storage medium, terms, yield curve andinterest rate volatility data for at least one municipal debt offering;receiving, by the computing system, IRS treatment data and applicabletax rates for the at least one municipal debt offering and a purchaserof the at least one municipal debt offering; calculating, by thecomputing system, a theoretical tax-neutral value of the at least onemunicipal debt offering using a buy-and-hold methodology, wherein thetax-neutral value includes the price of the at least one municipal debtoffering such that its discounted after-tax value equals the price;calculating, by the computing system, a theoretical maximum after-taxvalue of the at least one municipal debt offering using a recursivevaluation path dependent methodology; and determining, by the computingsystem, optimal management of the at least one municipal debt offeringusing the calculated theoretical tax-neutral value and maximum after-taxvalue of the at least one municipal debt offering.

A system for calculating the after-tax value of a municipal debtinstrument includes: a computer system comprising at least one processorand an operably connected data storage medium, wherein the at least oneprocessor is configured for receiving information associated with atleast one municipal debt offering and storing the received informationin the data storage medium, wherein the processor is further configuredfor directing the function of the following devices: a first receivingdevice configured to receive terms, yield curve and interest ratevolatility data for at least one municipal debt offering; a secondreceiving device configured to receive IRS treatment data and applicabletax rates for the at least one municipal debt offering and a purchaserof the at least one municipal debt offering; a first calculating deviceconfigured to calculate a theoretical tax-neutral value of the at leastone municipal debt offering using a buy-and-hold methodology, whereinthe tax-neutral value includes the price of the at least one municipaldebt offering such that its discounted after tax value equals the price;a second calculating device configured to calculate a theoreticalmaximum after-tax value of the at least one municipal debt offeringusing a recursive valuation path dependent methodology; and adetermining device configured to determine optimal management of the atleast one municipal debt offering using the calculated theoreticaltax-neutral value and maximum after-tax value of the at least onemunicipal debt offering.

A non-transitory computer readable storage medium having programinstructions stored thereon that, if executed by a computing device,cause the computing device to perform operations for calculating theafter-tax value of a municipal debt instrument, the operationsincluding: receiving, by a computing system including a processor and adata storage medium, terms, yield curve and interest rate volatilitydata for at least one municipal debt offering; receiving, by thecomputing system, IRS treatment data and applicable tax rates for the atleast one municipal debt offering and a purchaser of the at least onemunicipal debt offering; calculating, by the computing system, atheoretical tax-neutral value of the at least one municipal debtoffering using a buy-and-hold methodology, wherein the tax-neutral valueincludes the price of the at least one municipal debt offering such thatits discounted after-tax value equals the price; calculating, by thecomputing system, a theoretical maximum after-tax value of the at leastone municipal debt offering using a recursive valuation path dependentmethodology; and determining, by the computing system, optimalmanagement of the at least one municipal debt offering using thecalculated theoretical tax-neutral value and maximum after-tax value ofthe at least one municipal debt offering.

Aspects of the present disclosure also relate to systems, methods andnon-transitory computer readable medium for determining valuation andrisk analysis for tax-exempt municipal bonds on an after-tax basis. Asystem includes a communications interface, a data storage medium, adatabase, a processing server and a display device. The communicationsinterface is coupled to one or more data sources and one or moreexternal devices, and is configured to receive market price data, bonddata and tax data from among the one or more data sources for one ormore tax-exempt municipal bonds. The data storage medium stores programcode comprising an option-adjusted spread valuation engine and apredefined tax logic data interpretation process. The database isconfigured to store the received bond data and the received tax data.The bond data comprises terms, yield curve data and interest ratevolatility data for the one or more tax-exempt municipal bonds. The taxdata comprises IRS tax rate treatment data and applicable tax rates forthe one or more tax-exempt municipal bonds. The processing serverincludes at least one processor configured to execute the program code.Execution of the program code causes the option-adjusted spreadvaluation engine to: receive an indication of a specific bond among theone or more tax-exempt municipal bonds through the communicationsinterface; retrieve, from the database, the terms, the yield curve dataand the interest rate volatility data among the stored bond data for thespecific bond; and retrieve, from the database, the IRS tax ratetreatment data and the applicable tax rates among the stored tax datafor the specific bond. The option-adjusted spread valuation engine alsodetermines, according to the predefined tax logic data interpretationprocess, a tax-neutral fair value of the specific bond based on: (1) theretrieved terms; (2) the retrieved yield curve data and the retrievedinterest rate volatility data; (3) the retrieved IRS tax rate treatmentdata and the retrieved applicable tax rates; and (4) the market pricedata, such that the tax-neutral fair value is reflective of the marketprice data. The option-adjusted spread valuation engine also, using thedetermined tax-neutral fair value of the specific bond and the marketprice data, determines, according to a recursive valuation pathdependent methodology, indicators including: (a) a value of the specificbond enhanced by a tax option; (b) a value of the tax option; and (c)whether to sell the specific bond and take a loss, such that aperformance of the specific bond over a buy-and-hold policy is improved,by indicating when to sell the specific bond and by indicating when aloss for tax purposes will occur. The display device is configured toreceive and display the indicators for use by investors for optimal taxmanagement of the specific bond. The at least one processor isconfigured to update one or more of the indicators displayed on thedisplay device responsive to changes in at least one of the market pricedata and the interest rate volatility data for the specific bond.

BRIEF DESCRIPTION OF THE DRAWINGS

The accompanying drawings, which are incorporated herein and form partof the specification, illustrate exemplary embodiments of the presentdisclosure and, together with the description, further serve to explainprinciples, aspects and features of the present disclosure. Theexemplary embodiments are best understood from the following detaileddescription when read in conjunction with the accompanying drawings. Itis emphasized that, according to common practice, the various featuresof the drawings are not to scale. On the contrary, the dimensions of thevarious features are arbitrarily expanded or reduced for clarity.Included in the drawings are the following figures:

FIG. 1 is a diagram illustrating a system for the valuation and riskanalysis of municipal debt instruments in accordance with exemplaryembodiments;

FIG. 2 is a flowchart illustrating a method of determination valuationand risk management in accordance with an exemplary embodiment of thepresent disclosure;

FIG. 3 is a flowchart illustrating an exemplary calculation of thetax-neutral value of a municipal debt instrument;

FIG. 4 is a flowchart illustrating an exemplary determination of optimalmanagement for a municipal debt instrument;

FIG. 5 is a flowchart illustrating an exemplary determination of riskmeasures associated with a municipal debt instrument;

FIG. 6 is a graph of the tax-neutral value vs. coupon of 10-year bonds;

FIG. 7 is a graph of the duration of 10-year bonds of various coupons;and

FIG. 8 is a block diagram illustrating system architecture of a computersystem in accordance with exemplary embodiments.

FIG. 9 is an illustration of an example interactive graphical userinterface (GUI) for optimal management of one or more municipal debtofferings in accordance with an exemplary embodiment of the presentdisclosure.

The features and advantages of the present disclosure will become moreapparent from the detailed description set forth below when taken inconjunction with the drawings, in which like reference charactersidentify corresponding elements throughout. In the drawings, likereference numbers generally indicate identical, functionally similar,and/or structurally similar elements. Generally, the drawing in which anelement first appears is indicated by the leftmost digit(s) in thecorresponding reference number.

DETAILED DESCRIPTION

The present disclosure relates to systems and methods for determiningvaluation and risk analysis for municipal debt instruments to determineoptimal management of the municipal debt instruments. Embodiments of thesystems and methods disclosed herein determine and utilize a theoreticaltax-neutral value for the municipal debt instruments, such as, but notlimited to, bonds.

Definition of Terms

Bonds—In finance terms, a bond is a debt security in which theauthorized issuer owes the holders (“bondholders”) a debt and, dependingon the terms of the bond, is obliged to pay interest (referred to as the“coupon”) to use and/or to repay the principal at a later date, termedmaturity. A bond is a formal contract to repay borrowed money withinterest at fixed intervals (e.g., semiannual, annual, monthly, etc.).

Thus, a bond is like a loan, in that the holder of the bond is thelender (creditor), the issuer of the bond is the borrower (debtor), andthe coupon is the interest. Bonds provide the borrower with externalfunds to finance long-term investments or, in the case of governmentbonds, to finance current expenditure.

Bonds and stocks are both securities. The major difference between bondsand stocks is that stockholders have an equity stake in the company(i.e., they are owners), whereas bondholders have a creditor stake inthe company (i.e., they are lenders). Another difference is that bondsusually have a defined term, or maturity, after which the bond isredeemed. On the other hand, stocks may be outstanding indefinitely. Anexception to a defined term being associated with a bond is a consolbond, which has no maturity.

Nominal, Principal or Face Amount (often called “Par”)—The amount onwhich the issuer pays interest, and which, most typically, has to berepaid at the end of the term. Some structured bonds have what is knownas a redemption amount, which is different from the face amount, andwhich can be linked to the performance of particular assets (e.g., astock or commodity index, a foreign exchange rate, a fund, etc.). Thiscan result in an investor receiving less or more than his/her originalinvestment at maturity.

Issue Price—The price at which investors buy the bonds when they arefirst issued. The net proceeds that the issuer of the bond receives arethe issue price, minus the issuance fees/expenses. If the bond happensto be sold at an auction, the issue price can vary.

Maturity Date—The date on which the issuer has to repay the nominalamount. As long as all payments have been made during the life of thebond, the issuer has no more obligations to the bond holders after thematurity date. The length of time until the maturity date is oftenreferred to as the term, tenor, or maturity of a bond. The term of abond can be any length of time. Debt securities with a term of less thanone year are, however, generally considered to be money marketinstruments rather than bonds. The term of most bonds is up to thirtyyears. Of course, some bonds have been issued with terms of up to onehundred years, and some bonds have been issued that do not mature atall.

Coupon—The interest rate that the issuer pays to the bond holders.Typically, this rate is fixed throughout the life of the bond. However,for floating rate bonds, it can also vary with a money market index(e.g., the London Inter-Bank Offered Rate (LIBOR)), or it can be evenmore exotic. The name “coupon” originates from the fact that in thepast, physical bonds were issued which had actual coupons attached tothem. On the coupon date(s), the bond holder would give the coupon to abank in exchange for the payment of the principal and interest (e.g.,the face amount).

Coupon Dates—The dates on which the issuer pays the coupon to thebondholders. For a semi-annual bond the issuer pays a coupon every sixmonths.

Municipal Bonds

A municipal bond is a bond issued by a township, borough, city, state,U.S. Territory, local government, or their agencies. Interest incomereceived by holders of municipal bonds is typically exempt from federalincome tax, and often also from the income tax of the state in whichthey are issued. Although municipal bonds issued for certain purposes(e.g., private purposes) may not be tax exempt.

Municipal bonds are typically issued for the purpose of financing theinfrastructure needs of the issuing municipality. These needs varygreatly, but can include, for example, schools, roads, streets,highways, bridges, hospitals, public housing, sewer systems, watersystems, power systems, power utilities, and various other publicprojects. Essentially, through the purchase of a municipal bond, theinvestor is lending money to the issuer (i.e., the municipality) whopromises to repay to the investor the principal plus a fixed or variableamount of interest over time. These investors are called bondholders.Repayment periods can be as short as a few months (although this israre) to 20, 30, or 40 years, or even longer. Municipal bonds areguaranteed by the government agency of issue.

The municipal issuer that issues the municipal bonds, such as, forexample, townships, boroughs, states, cities, counties, etc., typicallydoes so to raise funds for public interest projects for which they donot have immediate funds at their disposal. Alternately, themunicipality may have the funds, but not desire to use them. Bonds bearan interest either at a fixed or a variable rate, and can be subject toeither, or both, minimum and/or maximum legal limits. Most municipalnotes and bonds are issued in minimum denominations of $5,000, ormultiples of $5,000.

In some instances, a bond measure may be used in order to sell bonds. Abond measure is an initiative to sell bonds for the purpose of acquiringfunds for various public works projects, such as, for example, research,transportation infrastructure improvements, educational improvements,and others. These bond measures are put up for a vote in generalelections, and must generally be approved by a majority of voters. Suchmeasures are often used in the United States when other revenue sources,such as taxes, are limited or non-existent.

Municipal bonds are generally a highly sought after investment becauseof their tax-exempt status. Income generated from the purchase of amunicipal bond may be exempt from federal, state or local income taxes,depending on the intent of the bond and the laws of each state. Forinstance, bonds issued for projects intended for the common good (i.e.,municipal bonds) are generally classified as tax exempt. Bonds that fundprojects for the benefit of private parties are not classified as taxexempt (e.g., offering bonds to support a company coming into the area).Typically, an investor will receives a lower interest rate payment onmunicipal bonds than on other private bonds because of their special taxexempt status (assuming comparable risk). This makes the issuance ofmunicipal bonds an attractive source of financing to many municipalentities, as the borrowing rate available in the open market isfrequently lower than what is available through other borrowingchannels.

Municipal bondholders purchase bonds either directly from the issuer atthe time of issuance (on the primary market), or from other bond holdersat some time after issuance (on the secondary market). In exchange foran upfront investment of capital, the bondholder receives payments overtime composed of interest on the invested principal, and a return of theinvested principal itself.

One of the primary reasons municipal bonds are considered separatelyfrom other types of bonds is their special ability to provide tax-exemptincome. Interest paid by the issuer to bondholders is often exempt fromall federal taxes, as well as state or local taxes, depending on thestate in which the issuer is located, subject to certain restrictions.However, bonds issued for certain purposes may be subject to thealternative minimum tax.

The type of project or projects that are funded by a bond affects thetaxability of income received on the bonds held by the bondholders.Interest earnings on bonds that fund projects that are constructed forthe public good are generally exempt from federal income tax. Interestearnings on bonds issued to fund projects partly or wholly benefitingonly private parties, sometimes referred to as private activity bonds,may be subject to federal income tax. However, qualified privateactivity bonds, whether issued by a governmental unit or private entity,are exempt from federal taxes because the bonds are financing servicesor facilities that, while meeting the private activity tests, are neededby a government.

Municipal securities consist of both short term issues (often callednotes, which typically mature in one year or less) and long term issues(commonly known as bonds, which mature after more than one year). Shortterm notes are typically used by an issuer to raise money for a varietyof reasons (e.g., in anticipation of future revenues such as taxes,state or federal aid payments, and future bond issuances; to coverirregular cash flows; meet unanticipated deficits; raise immediatecapital for projects until long term financing can be arranged; etc.).Bonds are usually sold to finance capital or public interest projectsover the longer term.

After-Tax Valuation

The present disclosure is an extension of the conventionalarbitrage-free bond valuation method (usually referred to as theoption-adjusted spread (OAS)) to incorporate taxes. In the absence oftaxes, the required inputs are the terms of the bond, and theappropriate yield curve and interest rate volatility. The output of theanalysis is the fair (pre-tax) value. A related application is todetermine the OAS given the bond's price.

With the present disclosure, similar calculations can be performed on anafter-tax basis. Present systems and methods may be implemented using anoption-free municipal yield curve.

The initial step in applying the present disclosure is the computationof the fair tax-neutral value of a bond under the buy-and-hold policy(“fair value”), which is the theoretical minimum. The fair valueprovides the foundation for three applications, namely, risk management,optimum tax management, and pricing.

The determination of fair value allows the present disclosure torigorously determine standard risk measures for a bond given its price.These risk measures include, but are not limited to, effective duration,effective convexity, and key rate durations. The interest ratesensitivity of a tax-exempt bond can be significantly greater than thatof like taxable bond. The fair value is also essential to determine theafter-tax performance of a bond under a specified interest rate scenarioover time (user-specified or computer-generated). In this case the fairtax-neutral value can be used to estimate future prices.

A fundamentally different application of the present disclosure is todetermine the optimal policy of managing bonds taking into account taxconsiderations. Astute investors realize that selling a bond at a lossmay be preferable to holding it until maturity: the loss can berecognized for tax purposes, and thus reduce taxes. The proceeds fromthe sale can be reinvested in a similar bond.

The basic problem in optimizing the tax strategy is to determine when tosell (e.g., when to take a loss). Relevant factors include transactioncost (bid-ask spread) and price volatility. During periods of decliningprices, repeated sales result in higher accumulated transaction costs,thus hindering performance.

Based on the present disclosure, methodology has been developed thatoptimizes after-tax performance. The methodology is implemented byrecursive valuation of a bond under a ‘path-dependent’ strategy—thedecision depends on the price at which the bond was purchased. However,recursive valuation of path-dependent bonds is analytically complex.

The present disclosure enables an investor to quantify the added valueof a bond over the ‘buy-and-hold’ strategy, assuming that it is managedoptimally from a tax perspective over its life. This added value isreferred to as the “embedded tax option”. As previously mentioned, thisvalue depends, among other things, on the volatility of prices (interestrates) and on bid-ask spreads. In addition, the value depends uponfuture bid/ask prices. In the ‘base case’, it is assumed that the bidprices are the fair values less transaction cost. Under realisticassumptions, the value of the tax option embedded in long-term municipalbonds (“munis”) can amount to several points (percent of face value).

The basic building block in the present disclosure is the tax-neutralvalue under the buy-and-hold policy, which is the theoretical minimumprice. Assuming that bonds trade in the vicinity of this fair value,investors can improve their performance over buy-and-hold by optimal taxmanagement. This insight can be incorporated into determining thepricing of the bond. Specifically, if trading near the fair value allowssophisticated investors to extract added value over buy-and-hold, themarket price of the bond could reflect this possibility. Thus, themarket price could by higher than the fair value. The question is by howmuch higher. The present disclosure allows an investor to determine thetheoretical maximum price (optimal tax arbitrage price). Given theminimum and the maximum, an average can be taken to estimate the priceused, for example, by mutual funds, to calculate net asset values at theend of the day.

System for the Valuation and Risk Analysis of Municipal Debt Instruments

FIG. 1 illustrates and exemplary system 100 for carrying out thedisclosed exemplary municipal bond valuation and risk analysis method.The system 100 can include a computing system 102 that includes aprocessing server 104, that includes a processor, and a data storagemedium 106 (e.g., random access memory (RAM) and/or read only memory(ROM)). Stored in the storage medium 106 are the various programs run onthe system 100 by the processor, as well as a data store or databaseincluding other information relevant to the disclosed system and method,such as, but not limited to terms, yield curve and interest ratevolatility data for the municipal debt instruments, and additionally IRStreatment data and application tax rates (income, short and long term,capital gains) for the municipal debt instruments and a purchaser 108 ofthe municipal debt instruments.

The various data with respect to the purchaser and the municipal debtoffering may be received by the computing system 102 from the purchaser108 through a purchaser computer device 110 via a network 112, and fromvarious other public and private computer devices and servers 114 viathe network 112. The network 112 may be any network suitable forperforming the functions as disclosed herein and may include a localarea network (LAN), a wide area network (WAN), a wireless network (e.g.,Wi-Fi), a mobile communication network, a satellite network, theInternet, fiber optic, coaxial cable, infrared, radio frequency (RF), orany combination thereof. Other suitable network types and configurationswill be apparent to persons having skill in the relevant art.

The storage medium 106 may include any type of suitable computerreadable media, such as, but not limited to, optical storage (e.g.,compact disc, digital versatile disc, Blu-ray disc, etc.) or magnetictape storage (e.g., hard disc drive). The storage medium 106 may beconfigured in any type of suitable database configuration, such as arelational database, a structured query language (SQL) database, adistributed database, an object database, etc. Suitable configurationsand database storage types will be apparent to persons having skill inthe relevant art. The databases may each be a single database, or maycomprise multiple databases which may be interfaced together (e.g.,physically or via a network, such as the network 112).

Method for Determining Valuation and Risk Management

FIG. 2 is a flowchart illustrating a method 200 of determinationvaluation and risk management in accordance with an exemplary embodimentof the present disclosure. FIG. 2 is described with continued referenceto the embodiment illustrated in FIG. 1 , but is not limited to thatembodiment.

Method 200 begins when bond series terms 202, yield curve and interestrate volatility data 206 and IRS treatment data and applicable tax rates206 are received by first and second receiving devices of the computingsystem 102. The first and second receiving devices may be the samedevice. The bond series terms 202 can quote to an issuer by variousunderwriters. The bonds being evaluated by method 200 may haverespective option-adjusted spreads determined based on correspondingyield curves relative to a benchmark yield curve and based on aninterest rate volatility factor. The yield curve date may include anysuitable benchmark yield curve, such as, but not limited to thosedisseminated by Municipal Market Data's (MMD), and Municipal MarketAdvisors (MMA).

In step 208, the various data 202, 204, 206 are passed to a firstcalculating device which calculates a theoretical tax-neutral value 210of the at least one municipal debt offering using a buy-and-holdmethodology, such that the tax-neutral value includes the price of theat least one municipal debt offering such that its discounted after-taxvalue equals the price. The various data 202, 204, 206 are also passedto a second calculating device which calculates a theoretical maximumafter-tax value 212 of the at least one municipal debt offering using arecursive valuation path dependent methodology. The theoretical maximumafter-tax value of the at least on municipal debt offering may becalculated using an issuer-specific optionless (par) yield curve fordiscounting and for valuing options at a specified interest ratevolatility. The first and second calculating devices may be the samedevice.

In step 214, the theoretical tax-neutral value 210 and the theoreticalmaximum after-tax value 212 are passed to as determining device whichdetermines optimal management 216 of the at least one municipal debtoffering using the calculated values 210, 212. The optimal management216 can include determining risk measure 218, estimating future prices220, identifying when to sell at a loss 222, calculating a theoreticalmaximum price 224, and/or calculating net asset value 226. In someembodiments, the optimal management 216 may also include identifying fora taxable issuer when to buy back bonds at a premium to book value onthe secondary market, such that the issuer can realize a tax benefit bypaying a higher price than the par or cost to the issuer of the bond ifheld to maturity. Methods for determining the optimal management 216 arediscussed in more detail below.

Method for Calculating the Tax-Neutral Value of a Municipal DebtInstrument

FIG. 3 is a flowchart illustrating an exemplary method 300 for thecalculation the tax-neutral value of a municipal debt instrument, suchas performed in step 210 of FIG. 2 . The method 300 begins when bondseries terms 302, yield curve and interest rate volatility data 304 andtax rates (income, short and long term, capital gains) 306 are received.The data 302, 304, 306 is passed to calculating device(s), such as anoption-adjusted spread valuation engine incorporating tax treatmentlogic, at step 308. The calculating device(s) calculates the after-taxvalue of the municipal debt instrument using the buy-and-holdmethodology, at step 310. Then, it is determined whether the calculatedafter-tax value equals the price of the municipal debt instrument, atstep 312. If the answer is “no”, a different price is utilized at step314, and steps 308, 310 and 312 are repeated. If the answer is “yes” atstep 312, the after-tax value is set as the tax-neutral value, at step316.

A detailed example of identifying the tax-neutral value of a municipaldebt instrument is discussed in more detail below with respect to FIG. 6.

Method for Determining Optimal Debt Management of a Municipal DebtInstrument

FIG. 4 is a flowchart illustrating an exemplary method 400 fordetermination of optimal management for a municipal debt instrument,such as the optimal management 216 of FIG. 2 . Method 400 begins whenbond series terms 402, yield curve and interest rate volatility data 404and tax rates (income, short and long term, capital gains) 406 arereceived. The data 402, 404, 406 is passed to calculating device(s),such as an option-adjusted spread valuation engine incorporating taxtreatment logic, at step 408. The calculating device(s) performsoperations using an option-adjusted spread (OAS) using a benchmark yieldcurve to calculate the tax-neutral value of the municipal debt offering,such that the tax-neutral value equals the market price, at step 410.The tax-neutral value is passed to an additional calculating device,such as an option-adjusted spread valuation engine, at step 412. Theoption-adjusted spread engine incorporate tax treatment and pathdependency, and also received market price 414 and purchase price/date416 data for the municipal debt offering. Depending on the path chosenfor the optimal management, the option adjusted spread engine at step412 calculates/determines: (a) the maximum after-tax value of themunicipal debt offering, at step 418; (b) the ‘tax option’ value, atstep 420; and (c) whether to sell the municipal debt offering and take aloss, at step 422. The indicators at steps 418, 420 and 422 can be usedby investors for optimal management of the municipal debt instrument.

At step 412, the option adjusted spread engine may, in addition oralternatively, calculate/determine the optimal time for a taxable issuerto buy back bonds at a premium to book value. In such an instance, theoptimal management of the bond may include determining the optimal timefor the issuer to take a tax loss, using the method 400 illustrated inFIG. 4 .

Method for Determining Risk Measures Associated with Municipal DebtInstruments

FIG. 5 is a flowchart illustrating an exemplary determination of riskmeasures associated with a municipal debt instrument. Method 500 beginswhen bond series terms 502, yield curve and interest rate volatilitydata 504 and tax rates (income, short and long term, capital gains) 506are received. The data 502, 504, 506 is passed to calculating device(s),such as an option-adjusted spread valuation engine incorporating taxtreatment logic, at step 508. The calculating device(s) performsoperations using an option-adjusted spread (OAS) using a benchmark yieldcurve to calculate the tax-neutral value of the municipal debt offering,such that the tax-neutral value equals the market price, at step 510.The tax-neutral value from step 512 is passed to an option-adjustedspread valuation engine, at step 512, which is similar to theoption-adjusted spread engine of step 508. However, the option-adjustedspread engine at step 512 also receives a ‘shocked’ benchmark yieldcurve (i.e. a benchmark yield that has been shifted up or down by acertain number of basis points, say 30 bps), at step 514, and calculatesshocked tax-neutral values using the shocked benchmark yield curve, atstep 516. The shocked tax-neutral values, as well as market price data520, are received at step 522. Using standard duration and convexityformulas at step 522, risk measurement values are determined at step524, which include parameters such as effective duration, effectiveconvexity and key rate durations.

Exemplary Implementation of Present Methods

As discussed above, while interest payments on municipal bonds aregenerally exempt from federal income taxes, capital gains and losses aresubject to complex tax treatment. Taxes affect investors' after-taxperformance. For example, because the gain on a bond purchased in thesecondary market at a discount and held to maturity is subject to taxes,the after-tax yield of the investment will be lower than the pre-taxyield. The prices of discounted tax-exempt bonds are routinely convertedto so-called after-tax cash flow yields to maturity. Converting price toan after-tax yield is straightforward, and it allows investors tocompare alternative investments on an-apples-to-apples basis.

The prices of tax-exempt bonds generally reflect these complex taxconsiderations. In the present disclosure, the conventionalarbitrage-free method of bond valuation (the so-called OAS approach) isextended to incorporate tax effects. First, the tax-neutral (“fair”)value of a bond assuming a buy-and-hold policy is determined asillustrated in FIG. 3 and discussed above. This fair value provides thebasis for rigorous risk analysis. As will be seen, the interest ratesensitivity of a municipal bond can be significantly greater than thatof a like taxable bond.

The implications of this observation are far-reaching. At the present,standard commercially available analytical systems do not take taxesinto account. This is particularly troublesome in the case of ETF's andmutual funds that attempt to replicate the performance of a largeindex—which may consist of over 10,000 bonds—with a few hundredsecurities. Matching durations on a pre-tax basis does not assure thatthe same relationship holds when the effect of taxes is properlyaccounted for. In light of this, the large tracking errors of these“index-matching” portfolios do not come as a surprise.

Investors who purchase a bond in the secondary market at a discount andhold it to maturity or call are taxed on the gain. At a modest discountto par (a so-called de minimis discount, defined as less than 0.25 timesthe number of years remaining to maturity), the applicable rate is therelatively low capital gains rate (at or around the time of drafting,15% if long-term). If the discount exceeds the de minimis threshold, theentire gain is taxed at the higher ordinary income rate (35% at the timeof drafting). It is also noted that the loss on a bond purchased at apremium and held to maturity has no tax effect.

To determine the tax-neutral value (“fair value”) of tax-exemptmunicipal bonds, an arbitrage-free analysis method may be used such asillustrated in FIG. 3 and discussed above. In the absence of taxes andoptions, the fair value may be obtained by discounting prospective cashflows at the appropriate spot rates. If options are present, suchdiscounting is performed on a lattice. The taxation of municipal bondscomplicates the calculation, because the cash flows depend on thepurchase price; roughly speaking, the lower the purchase price the moretaxes will be due when the bond is retired.

As discussed above, the tax-neutral (fair) value is defined as the pricewhich is equal to the present value of future after-tax cash flows(i.e., interest and principal payments minus the taxes paid at the timeof redemption). Simply put, the fair value is the “pretax” valueadjusted for taxes. Because taxes depend on the purchase price, in thecase of a callable bond, the fair value has to be determinediteratively, as the timing of the tax payment depends on the evolutionof interest rates. The calculation can be simplified if the bond isoptionless, as illustrated below.

Assume the bond has 10 years remaining to maturity, its pretax value is80, the discount factor for a cash flow occurring 10 years from now is0.40, and the tax rate applicable to the gain is 35%.

Solving V=80−0.4*0.35*(100−V) gives the fair value V=76.744.

Next, the fair values of various structures are determined. Forcomparison purposes, the values are also shown in the absence of taxes.The calculations are based on the yield curve displayed in Table 1below. The assumed base case volatility is 20%. The long-term capitalgains rate is 15%, and the tax rate applicable to ordinary income rateis 35%.

TABLE 1 Issuer's Optionless Par Yield Curve Maturity (yrs) 1 2 5 10 1520 30 Rate (%) 1.0 1.5 2.0 3.0 3.5 4.0 4.5

Initially, as shown in FIG. 6 , it is noted that the pre-tax value of adiscount muni exceeds its fair value by the present value of the taxespaid at the time the bond is redeemed. Here, the de minimis threshold is97.50% of par (100−10*0.25). In the absence of taxes, a bond with a2.72% coupon would be valued at 97.50%, but the tax on the gain reducesthe value. Standing out in FIG. 6 is how the fair value “falls off thecliff” at this level. The “critical” coupon (discussed below) is 2.75%.But if the coupon is 2.74%, the fair value declines by 0.60% to 96.90%.The obvious reason is that above 97.50% the gain is taxed at the 15%capital gains rate, but below 97.50% the gain would be taxed at 35%.

As seen in the example above, for the given yield curve and bondstructure (i.e., maturity and optionality) there is a theoretical couponlevel where the fair value declines discontinuously (falls off thecliff). While in reality the price decline is not as abrupt as indicatedby the disclosed model, this critical coupon level is still of practicalinterest. If a bond is purchased at a price slightly above the deminimis threshold, its price could take a large hit if rates risemodestly. Because the market anticipates this possibility, the priceexperiences downward pressure even though the bond has a coupon abovethe critical level. In a like manner, the prices can be higher thanpredicted by the present model if the coupon is slightly lower than thecritical level.

For a given yield curve and optionless bond, the critical coupon can bedetermined in a straightforward manner.

Assume that the present value of a 10-year $1 annuity is $8.50, thediscount factor for a cash flow occurring 10 years from now is 0.70, andthe capital gains rate is 15%.

Solving 8.50*C+0.70*(100−0.15*2.5)=97.50 results in C=3.27%.

Note that the fair value of a bond whose coupon is slightly below 3.27%is 97.50−0.70*(0.35−0.15)*2.50, or 97.15%.

In the case of tax-exempt bonds, it is imperative to recognize that theprices incorporate potential tax effects; otherwise the interest ratesensitivity can be severely underestimated. The intuition is clear:higher rates depress the price, and a lower price increases taxes. This,in turn, puts additional pressure on the price, etc., until theiteration converges to the fair value.

Naturally, the higher the applicable tax rate the greater is the aboveeffect, so it is most pronounced when the price is below the de minimisthreshold. At the de minimis threshold, the price is discontinuous and,therefore, interest rate sensitivity is not defined. Whenever the taxtreatment is discontinuous, it is desirable to distinguish between “up”and “down” durations.

FIG. 7 displays the durations of 10-year optionless bonds. Recall thatthe critical coupon in this case is 2.75% (see FIG. 6 ). The durationsof bonds with coupons below 2.75% exceeds 12 years, which is 2 yearslonger than the bonds' maturity. And durations exceed 10 years slightlyeven when the price is above the de minimis region (coupons larger than2.75%).

Since the pretax duration of a bond cannot exceed the bond's maturity,any calculator that disregards taxes will severely underestimate thetrue duration of discount bonds. But the error is significant even ifthe price is close to par. For example, the pretax duration of a 3.00%bond is 8.85 years, which is considerably shorter than 10 years.

As described previously, interest rate risk measures are calculatedusing a fixed OAS relative to a benchmark yield curve. (A naive anderroneous approach is to use a fixed YTM or YTC spread to a givenbenchmark maturity.) It should be recognized that the OAS depends onwhether or not the given price is assumed to reflect tax effects.

Suppose that the price of an optionless 10-year 2.5% bond is 84.15%;calculate its OAS relative to the benchmark curve given earlier.

Pretax: OAS=148 bps, duration=8.87 years.

Tax-adjusted: OAS=100 bps, duration=12.15 years.

The important observation is that correct calculation of interest raterisk requires an explicit adjustment for taxes. In the absence of such,the risk of tax-exempt bonds is underestimated.

Accordingly, using tax-neutral values as a foundation, it has been shownherein that the interest rate sensitivity of tax-exempt bonds can besignificantly greater than indicated by pre-tax calculations, which hasbeen the standard in the industry. The difference is most pronounced forshorter-term bonds selling below the de minimis level, whose durationcan exceed their maturity by several years.

In light of the fact that under current practice the interest ratesensitivity of tax-exempt bonds is misspecified, the large trackingerrors of “index-matched” ETF's and mutual funds are not surprising.Tax-adjusted analytics are essential for proper management of tax-exemptbond portfolios.

Computer System Architecture

FIG. 8 illustrates a computer system 800 in which embodiments of thepresent disclosure, or portions thereof, may be implemented ascomputer-readable code. For example, the computing system 102, theprocessing server 104, the purchaser computer device 110, and theprivate computer devices and servers 114 of FIG. 1 may be implemented inthe computer system 800 using hardware, software, firmware,non-transitory computer readable media having instructions storedthereon, or a combination thereof and may be implemented in one or morecomputer systems or other processing systems. Hardware, software, or anycombination thereof may embody modules and components used to implementthe methods of FIGS. 2-6 .

If programmable logic is used, such logic may execute on a commerciallyavailable processing platform or a special purpose device. A personhaving ordinary skill in the art may appreciate that embodiments of thedisclosed subject matter can be practiced with various computer systemconfigurations, including multi-core multiprocessor systems,minicomputers, mainframe computers, computers linked or clustered withdistributed functions, as well as pervasive or miniature computers thatmay be embedded into virtually any device. For instance, at least oneprocessor device and a memory may be used to implement the abovedescribed embodiments.

A processor device as discussed herein may be a single processor, aplurality of processors, or combinations thereof. Processor devices mayhave one or more processor “cores”. The terms “computer program medium”,“non-transitory computer readable medium”, and “computer usable medium”as discussed herein are used to generally refer to tangible media suchas a removable storage unit 818, a removable storage unit 822, and ahard disk installed in hard disk drive 812.

Various embodiments of the present disclosure are described in terms ofthis example computer system 800. After reading this description, itwill become apparent to a person skilled in the relevant art how toimplement the present disclosure using other computer systems and/orcomputer architectures. Although operations may be described as asequential process, some of the operations may in fact be performed inparallel, concurrently, and/or in a distributed environment, and withprogram code stored locally or remotely for access by single ormulti-processor machines. In addition, in some embodiments the order ofoperations may be rearranged without departing from the spirit of thedisclosed subject matter.

The computer system 800 includes a display 830 connected to acommunications infrastructure 806 via a display interface 802. In anembodiment, the display 830, in conjunction with the display interface802, provides a user interface (UI) for clients and purchasers. Thecomputer system 800 also includes a processor device 804, which may be aspecial purpose or a general purpose processor device. The processordevice 804 may be connected to a communication infrastructure 806, suchas a bus, message queue, network (e.g., the network 18), multi-coremessage-passing scheme, etc. The computer system 800 may also include amain memory 808 (e.g., random access memory, read-only memory, etc.),and may also include a secondary memory 810. The secondary memory 810may include the hard disk drive 812 and a removable storage drive 814,such as a floppy disk drive, a magnetic tape drive, an optical diskdrive, a flash memory, etc.

The removable storage drive 814 may read from and/or write to theremovable storage unit 818 in a well-known manner. The removable storageunit 818 may include a removable storage media that may be read by andwritten to by the removable storage drive 814. For example, if theremovable storage drive 814 is a floppy disk drive, the removablestorage unit 818 may be a floppy disk. In one embodiment, the removablestorage unit 818 may be non-transitory computer readable recordingmedia.

In some embodiments, the secondary memory 810 may include alternativemeans for allowing computer programs or other instructions to be loadedinto the computer system 800, for example, the removable storage unit822 and an interface 820. Examples of such means may include a programcartridge and cartridge interface (e.g., as found in video gamesystems), a removable memory chip (e.g., EEPROM, PROM, etc.) andassociated socket, and other removable storage units 822 and interfaces820 as will be apparent to persons having skill in the relevant art.

The computer system 800 may also include a communications interface 824.The communications interface 824 may be configured to allow software anddata to be transferred between the computer system 800 and externaldevices. Exemplary communications interfaces 824 may include a modem, anetwork interface (e.g., an Ethernet card), a communications port, aPCMCIA slot and card, etc. Software and data transferred via thecommunications interface 824 may be in the form of signals 828, whichmay be electronic, electromagnetic, optical, or other signals capable ofbeing received by the communications interface 824, as will be apparentto persons having skill in the relevant art. The signals 828 may travelvia a communications path 826, which may be configured to carry thesignals and may be implemented using wire, cable, fiber optics, a phoneline, a cellular phone link, a radio frequency link, etc.

Computer program medium and computer usable medium may refer tomemories, such as the main memory 808 and secondary memory 810, whichmay be memory semiconductors (e.g., DRAMs, etc.). These computer programproducts may be means for providing software to the computer system 800.Computer programs (e.g., computer control logic) may be stored in themain memory 808 and/or the secondary memory 810. Computer programs mayalso be received via the communications interface 824. Such computerprograms, when executed, may enable computer system 800 to implement thepresent methods as discussed herein. In particular, the computerprograms, when executed, may enable processing server 104 to implementthe methods illustrated by FIGS. 2-6 , as discussed herein. Accordingly,such computer programs may represent controllers of the computer system800. Where the present disclosure is implemented using software, thesoftware may be stored in a computer program product and loaded into thecomputer system 800 using the removable storage drive 814, interface820, and hard disk drive 812, or communications interface 824.

FIG. 9 is an illustration of an example interactive GUI 900 for optimalmanagement of municipal debt offerings, according to an aspect of thepresent disclosure. GUI 900 may include one or more windows 902 havingvarious regions (e.g., regions 904-920) for interaction with valuationand risk management metrics (e.g., measures) for one or more municipaldebt offerings. Although exemplary regions are depicted in FIG. 9 ,alternate configurations for the regions are envisioned. For example, agraphical user interface may contain more or fewer regions.Additionally, the regions may be reorganized in any manner and displayother pertinent information. Moreover one or more of regions 904-920 mayprovide for presentation of and user interaction with data andinformation. In some examples, region 906 may represent various analysisresults of optimal bond management 216 (FIG. 2 ).

In some examples, window 902 of interactive GUI 900 may include userinput region 904, interactive results display region 906 and, in someexamples, (optional) user action region 920.

Region 904 may provide any suitable user input tools such as buttons,text boxes, radio dials, pop-up windows, drop down menus, selectors andthe like for providing user input into interactive GUI 900. In someexamples, region 904 may include user input options for indicating aspecific municipal debt offering (e.g., by selecting from apredetermined list, text input of a specific offering, selection basedon a search, etc.) for determining (by computing system 102) optimalmanagement metrics for the specific offering. In some examples, region904 may be used to indicate one or more desired parameters for thevaluation/risk analysis and/or additional characteristics of thespecific offering. In some examples, region 904 may be used to selectone or more metrics in region 906 to be analyzed as part of the optimalmanagement analysis (e.g., as part of the valuation/risk analysisperformed by computing system 102). In some examples, one or more ofregions 908-918 (and, in some examples, region 920) nay be updated inresponse to any user input in region 904. Although region 904 isillustrated as being separate from regions 906-918 (and optional region920, it is understood that region 904 may be part of one or more ofregions 906-918 and 920.

Although not shown, in some examples, interactive GUI 900 may includeone or more regions for providing one or more of market data, bond data(e.g., terms, yield curve data, interest rate volatility data) and taxdata (e.g., IRS treatment data, applicable tax rates) for the specific(user-selected) offering to be analyzed. In some examples, one or moreof regions 904, 906 and 920 may be updated in response to changes in anydata (e.g., market data, bond data, and/or tax data) used by computingsystem 102 to determine optimal management metrics (and, in someexamples available user actions in region 920). For example, one or moremetrics (e.g., one or more indicators in region 906) may be updatedresponsive to any changes in the market price data and/or the interestrate volatility data.

Region 906 may include one or more regions for providing optimalmanagement metrics for a specific municipal debt offering (selected by auser in region 904). For example, region 906 may include risk metricsregion 908, future price estimator metrics region 910, when to sellmetrics region 912, fair price calculator metrics region 914,theoretical maximum price metrics region 916 and when to buy backmetrics region 918. Each metric may be presented as one or moreindicators. Each of regions 908-918 may present the indicator(s) in oneor more of a text format, a graphical format, as well as any othersuitable format. In some examples, one or more of regions 908-918 mayprovide additional information related to the particular metric. In someexamples, one or more of regions 908-918 may include one or more userinput regions for interacting with a particular metric, where user inputmay cause the particular region to display additional information and/orupdate the existing metric indicator(s) and/or other informationassociated with the metric.

Risk metrics region 908 may provide (interactive) metrics determined byrisk measure 218 (FIG. 2 ). Future price estimation metrics region 910may provide (interactive) metrics based on estimated future prices 220(FIG. 2 ). When to sell metrics region 912 may provide (interactive)metrics on the determination of when to sell at a loss 222 (FIG. 2 ).Fair price calculator metrics region 914 may provide (interactive)metrics based on calculation of a fair price (net asset value) 226 (FIG.2 ). Theoretical maximum price metrics region 916 may provide(interactive) metrics on determined theoretical maximum price 224 (FIG.2 ). When to buy back metrics region 918 may provide (interactive)metrics on when to buy back a municipal debt offering (e.g., a municipalbond) at a premium to book value on a secondary market, such that theissuer can realize a tax benefit (e.g., by paying a higher price thanthe par or cost to the issuer of the bond if it is held to maturity).

In some examples, optional user action region 920 may provideuser-selectable options to buy, sell and/or modify a municipal debtoffering. In some examples, different options may be presented (and/orbe active for selection) in user action region 920, depending upon ametric region among regions 908-918) currently selected by a user (inregion 906). For example, when region 912 is currently selected, useraction region 920 may include an active selectable option to sell aspecific offering. As another example, when region 918 is selected, useraction region 920 may include an active selectable option to buy back aspecific offering. In some examples, selection of a user action in useraction region 920 may cause computing system 102 to initiate theselected user action (e.g., buy, sell, modify a specific offering) withat least one entity (e.g. at least one market such as a primary marketand/or a secondary market, a bondholder, an issuer, a purchaser and thelike). In some examples, user selectable actions in region 920 mayinclude additional options for user input, such as a time period and/ordate in which to perform the requested action.

In some examples, interactive GUI 900 may represent an example of the UIdiscussed above (e.g., display 830 in conjunction with display interface802 (FIG. 8 )). It should be understood that FIG. 9 represents anon-limiting example user interface, and that a differing interfaceconfigured in accordance with this disclosure may be provided forproviding interactive presentation (and, in some examples, additionalactions) with optimal management metrics for specific municipal debtofferings selectable by a user.

Techniques consistent with the present disclosure provide, among otherfeatures, systems and methods for the calculating of the after-tax valueof a municipal debt instrument. While various exemplary embodiments ofthe disclosed system and method have been described above it should beunderstood that they have been presented for purposes of example only,not limitations. It is not exhaustive and does not limit the disclosureto the precise form disclosed. Modifications and variations are possiblein light of the above teachings or may be acquired from practicing ofthe disclosure, without departing from the breadth or scope.

It should also be understood that all references identified and/orreferenced herein are incorporated fully by reference herein in thereentireties.

1. A non-transitory computer readable medium containing program code forcausing at least one processor to perform the method of: receiving, by acommunications interface coupled to one or more data sources and one ormore external devices, market price data, bond data and tax data fromamong the one or more data sources for one or more tax-exempt municipalbonds, the program code comprising an option-adjusted spread valuationengine and a predefined tax logic data interpretation process; storing,in a database, the received bond data and the received tax data, thebond data comprising terms, yield curve data and interest ratevolatility data for the one or more tax-exempt municipal bonds, the taxdata comprising IRS tax rate treatment data and applicable tax rates forthe one or more tax-exempt municipal bonds; executing the program codecausing the option-adjusted spread valuation engine to perform the stepsof: receiving an indication of a specific bond among the one or moretax-exempt municipal bonds through the communications interface;retrieving, from the database, the terms, the yield curve data and theinterest rate volatility data among the stored bond data for thespecific bond; retrieving, from the database, the IRS tax rate treatmentdata and the applicable tax rates among the stored tax data for thespecific bond; determining, according to the predefined tax logic datainterpretation process, a tax-neutral fair value of the specific bondbased on: (1) the retrieved terms, (2) the retrieved yield curve dataand the retrieved interest rate volatility data; (3) the retrieved IRStax rate treatment data and the retrieved applicable tax rates and (4)the market price data, such that the tax-neutral fair value isreflective of the market price data; and using the determinedtax-neutral fair value of the specific bond and the market price data,determining, according to a recursive valuation path dependentmethodology indicators including: (a) an option-enhanced valuecomprising a value of the specific bond enhanced by a tax option; (b) avalue of the tax option; and (c) whether to sell the specific bond andtake a loss, such that a performance of the specific bond over abuy-and-hold policy is improved, by indicating when to sell the specificbond and by indicating when a loss for tax purposes will occur;displaying, on a display device, the indicators, wherein the indicatorsare used by investors for optimal tax management of the specific bond;and updating one or more of the indicators displayed on the displaydevice responsive to changes in at least one of the market price dataand the interest rate volatility data for the specific bond.
 2. Thenon-transitory computer readable medium of claim 1, wherein the value ofthe tax-option is determined by subtracting the tax-neutral fair valuefrom the option-enhanced value.
 3. The non-transitory computer readablemedium of claim 1, wherein the step of determining the indicatorscomprises: determining, using the tax-neutral fair value, risk measuresfor the specific bond given its price, wherein the risk measurescomprise at least one of effective duration, effective convexity and keyrate durations.
 4. The non-transitory computer readable medium of claim1, further comprising: determining an option-adjusted spread of thespecific bond at a given price relative to a benchmark yield curve; anddetermining the tax-neutral fair value of the municipal bond at thedetermined option-adjusted spread.
 5. The non-transitory computerreadable medium of claim 1, wherein the step of determining theindicators comprises: estimating future prices of the specific bondunder a specified interest rate scenario over time.
 6. Thenon-transitory computer readable medium of claim 1, wherein the step ofdetermining the indicators comprises: determining, using the tax-neutralfair value and the option-enhanced value, when to sell the specific bondat a loss.
 7. The non-transitory computer readable medium of claim 1,wherein the step of determining the indicators comprises: determining,using the tax-neutral fair value and the option-enhanced value, thevalue of the tax option for the specific bond.
 8. The non-transitorycomputer readable medium of claim 7, further comprising: setting thetax-neutral fair value as a minimum price for the specific bond.
 9. Thenon-transitory computer readable medium of claim 1, wherein the termsinclude interest payments to be made at least one of periodically and atmaturity.
 10. The non-transitory computer readable medium of claim 1,wherein the yield curve data comprises at least one benchmark yieldcurve.
 11. A method of determining valuation and risk analysis fortax-exempt municipal bonds on an after-tax basis, the method comprising:providing a computing system including a communications interface, adata storage medium, a database, a processing server and a displaydevice, the communications interface coupled to one or more data sourcesand one or more external devices, the data storage medium storingprogram code comprising an option-adjusted spread valuation engine and apredefined tax logic data interpretation process, the processing serverincluding at least one processor configured to execute the program code;receiving, by the communications interface, market price data, bond dataand tax data from among the one or more data sources for one or moretax-exempt municipal bonds; storing, in the database, the received bonddata and the received tax data, the bond data comprising terms, yieldcurve data and interest rate volatility data for the one or moretax-exempt municipal bonds, the tax data comprising IRS tax ratetreatment data and applicable tax rates for the one or more tax-exemptmunicipal bonds; executing, by the processing server, the program codecausing the option-adjusted spread valuation engine to perform the stepsof: receiving an indication of a specific bond among the one or moretax-exempt municipal bonds through the communications interface;retrieving, from the database, the terms, the yield curve data and theinterest rate volatility data among the stored bond data for thespecific bond; retrieving, from the database, the IRS tax rate treatmentdata and the applicable tax rates among the stored tax data for thespecific bond; determining, according to the predefined tax logic datainterpretation process, a tax-neutral fair value of the specific bondbased on: (1) the retrieved terms; (2) the retrieved yield curve dataand the retrieved interest rate volatility data; (3) the retrieved IRStax rate treatment data and the retrieved applicable tax rates; and (4)the market price data, such that the tax-neutral fair value isreflective of the market price data; and using the determinedtax-neutral fair value of the specific bond and the market price data,determining, according to a recursive valuation path dependentmethodology, indicators including: (a) a value of the specific bondenhanced by a tax option; (b) a value of the tax option; and (c) whetherto sell the specific bond and take a loss, such that a performance ofthe specific bond over a buy-and-hold policy is improved, by indicatingwhen to sell the specific bond and by indicating when a loss for taxpurposes will occur; displaying, on the display device, the indicators,wherein the indicators are used by investors for optimal tax managementof the specific bond; and updating, by the at least one processor, oneor more of the indicators displayed on the display device responsive tochanges in at least one of the market price data and the interest ratevolatility data for the specific bond.
 12. The method of claim 11,wherein the step of determining the indicators further comprises:determining, using the tax-neutral fair value, risk measures for thespecific bond given its price, wherein the risk measures comprise atleast one of effective duration, effective convexity and key ratedurations.
 13. The method of claim 11, wherein the step of determiningthe indicators further comprises: estimating future prices of thespecific bond under a specified interest rate scenario over time. 14.The method of claim 11, wherein the terms include interest payments tobe made at least one of periodically and at maturity.
 15. A system todetermine valuation and risk analysis for tax-exempt municipal bonds onan after-tax basis, comprising: a communications interface coupled toone or more data sources and one or more external devices, thecommunications interface configured to receive market price data, bonddata and tax data from among the one or more data sources for one ormore tax-exempt municipal bonds; a data storage medium storing programcode comprising an option-adjusted spread valuation engine and apredefined tax logic data interpretation process; a database configuredto store the received bond data and the received tax data, the bond datacomprising terms, yield curve data and interest rate volatility data forthe one or more tax-exempt municipal bonds, the tax data comprising IRStax rate treatment data and applicable tax rates for the one or moretax-exempt municipal bonds; a processing server including at least oneprocessor configured to execute the program code, execution of theprogram code causing the option-adjusted spread valuation engine to:receive an indication of a specific bond among the one or moretax-exempt municipal bonds through the communications interface;retrieve, from the database, the terms, the yield curve data and theinterest rate volatility data among the stored bond data for thespecific bond; retrieve, from the database, the IRS tax rate treatmentdata and the applicable tax rates among the stored tax data for thespecific bond; determine, according to the predefined tax logic datainterpretation process, a tax-neutral fair value of the specific bondbased on: (1) the retrieved terms; (2) the retrieved yield curve dataand the retrieved interest rate volatility data; (3) the retrieved IRStax rate treatment data and the retrieved applicable tax rates; and (4)the market price data, such that the tax-neutral fair value isreflective of the market price data; and using the determinedtax-neutral fair value of the specific bond and the market price data,determine, according to a recursive valuation path dependentmethodology, indicators including: (a) a value of the specific bondenhanced by a tax option; (b) a value of the tax option; and (c) whetherto sell the specific bond and take a loss, such that a performance ofthe specific bond over a buy-and-hold policy is improved, by indicatingwhen to sell the specific bond and by indicating when a loss for taxpurposes will occur; and a display device configured to receive anddisplay the indicators for use by investors for optimal tax managementof the specific bond, the at least one processor configured to updateone or more of the indicators displayed on the display device responsiveto changes in at least one of the market price data and the interestrate volatility data for the specific bond.
 16. The system of claim 15,wherein the processing server is further configured to determine, usingthe tax-neutral fair value, risk measures for the specific bond givenits price, the risk measures comprising at least one of effectiveduration, effective convexity and key rate durations.
 17. The system ofclaim 15, wherein the processing server is further configured toestimate future prices of the specific bond under a specified interestrate scenario over time.
 18. The system of claim 15, wherein the termsinclude interest payments to be made at least one of periodically and atmaturity.